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sim-se: Fix mremap for downward growing mmap regions

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mremapFunc(...) did not respect Process::mmapGrowsDown(). This resulted
in an attempt to remap into an already allocated region and a panic in
FuncPageTable::allocate(...). This behavior can be observed in
435.gromacs.

Change-Id: Ib3ad33816126c76506d69679bdcefa7a98ef69f9
Reviewed-on: https://gem5-review.googlesource.com/4700
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
This commit is contained in:
Rico Amslinger
2017-09-18 13:44:06 +02:00
parent 0b77e05cb2
commit 1ff5e31e53
1 changed files with 15 additions and 5 deletions
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20
src/sim/syscall_emul.hh
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@@ -932,6 +932,8 @@ mremapFunc(SyscallDesc *desc, int callnum, Process *process, ThreadContext *tc)
if ((start + old_length) == mmap_end &&
(!use_provided_address || provided_address == start)) {
// This case cannot occur when growing downward, as
// start is greater than or equal to mmap_end.
uint64_t diff = new_length - old_length;
process->allocateMem(mmap_end, diff);
mem_state->setMmapEnd(mmap_end + diff);
@@ -941,8 +943,15 @@ mremapFunc(SyscallDesc *desc, int callnum, Process *process, ThreadContext *tc)
warn("can't remap here and MREMAP_MAYMOVE flag not set\n");
return -ENOMEM;
} else {
uint64_t new_start = use_provided_address ?
provided_address : mmap_end;
uint64_t new_start = provided_address;
if (!use_provided_address) {
new_start = process->mmapGrowsDown() ?
mmap_end - new_length : mmap_end;
mmap_end = process->mmapGrowsDown() ?
new_start : mmap_end + new_length;
mem_state->setMmapEnd(mmap_end);
}
process->pTable->remap(start, old_length, new_start);
warn("mremapping to new vaddr %08p-%08p, adding %d\n",
new_start, new_start + new_length,
@@ -951,10 +960,11 @@ mremapFunc(SyscallDesc *desc, int callnum, Process *process, ThreadContext *tc)
process->allocateMem(new_start + old_length,
new_length - old_length,
use_provided_address /* clobber */);
if (!use_provided_address)
mem_state->setMmapEnd(mmap_end + new_length);
if (use_provided_address &&
new_start + new_length > mem_state->getMmapEnd()) {
((new_start + new_length > mem_state->getMmapEnd() &&
!process->mmapGrowsDown()) ||
(new_start < mem_state->getMmapEnd() &&
process->mmapGrowsDown()))) {
// something fishy going on here, at least notify the user
// @todo: increase mmap_end?
warn("mmap region limit exceeded with MREMAP_FIXED\n");